Standard series of rapid hollow absorbers

Abstract

A standard series of rapid hollow absorbers with an output ranging from 5000 to 65000 m 3 /h of cleaned gases is developed. The absorbers are intended for readily soluble gases (HCl, HF, SO 2 , etc.). The series includes five standard sizes of scrubbers 600, 900, 1200, 1600, and 2000 mm in diameter. Technical data are presented for the scrubbers.The MGUIE has developed a detailed design for a standard-size series of rapid hollow absorbers with an output of cleaned gases ranging from 5000 to 65000 m 3 /h. The vessels comprising this series are intended for the absorption of readily soluble gases (HCl, HF, SO 2 , etc.). The series includes five standard sizes of scrubbers 600, 900, 1200, 1600, and 2000 mm in diameter. The average velocity of the gases in the free section of a vessel is 5.5 m/sec, and the reflux density is 35-55 m 3 /(m 2 ·h). Three tiers of mechanical injectors (three in each tier) are established within the absorbers.The absorber ( Fig. 1) with a diameter D consists of a cylindrical hollow metallic housing with a conical bottom, lower intake pipe for waste gases, an outlet pipe for the cleaned gases, and three reflux collectors.The collector, which is intended for uniform distribution and feed of absorbent to the injectors, is mounted external to the absorber -above the injectors to eliminate the formation of stagnant zones when the feed of absorbent is curtailed.The liquid is atomized by mechanical centrifugal-jet injectors (Fig. 2) with a spray-cone angle of 120°(d n is the diameter of the nozzle). Nine injectors are established in the vessel. The spray cone of the injectors in the lower tier is directed upward (along the path of the gas), while those in the upper and middle tiers are directed downward; this ensures optimal contact conditions between the gases being cleaned and the irrigating liquid. The distance between tiers is 2.5 m.The number of injectors in a tier, and their arrangement are selected from the condition whereby the section of the absorber is covered by cone sprays for the assigned reflux densities. The injectors in each tier are shifted 40°with respect to another tier for complete coverage of the free section of the absorber by the liquid spray.Injectors with nozzles ranging from 6 to 22 mm in diameter are mounted as a function of the required flow rate of absorbent. The pressure of the liquid supplied for the spray can be varied in cases when it is required to adjust the flow rate of absorbent.Since the absorbers operate at high gas-flow velocities, and the average drop size in the injectors employed under an atomizing pressure of 0.2 MPa, which is calculated in accordance with the procedure proposed in [1], ranges from 370 to 810 µm, rather vigorous splashing and carry-off take place during their operation. According to Prikhod'ko [2], splash and carry-off amount to 177-304 liters/m 3 when the reflux density is 35-55 m 3 /(m 2 ·h), and the velocity of the gas flow is 5.5 m/sec. In the upper section of the vessels, therefore, it is necessary to mount a TsKKZ type of centrifu...